Revert "Remove empty closed paths"

This reverts commit 572074cb06425797e7e110511db405134cf67e2f.

Reason for revert:
caused regression bug: crbug.com/1521614

Original change's description:
> Remove empty closed paths
>
> As discussed in the github issue,
> whatwg/html#1079, it's generally agreed to
> skip drawing line caps for closed paths. This is a follow up cl of:
> https://chromium-review.googlesource.com/c/chromium/src/+/4864061.
>
> In this cl, it verifies if each closed path is empty, then it removes
> the empty closed subpaths from path. As the subpaths are removed, the
> corresponding line caps are skipped.
>
> Bug: 644067
>
> Change-Id: I14c5c4819a31eb9249d01574ff1b5c60826c3b9e
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4916516
> Commit-Queue: Yi Xu <yiyix@google.com>
> Reviewed-by: Jean-Philippe Gravel <jpgravel@chromium.org>
> Reviewed-by: Justin Novosad <junov@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1247735}

Bug: 644067
Change-Id: I33ecfd76574d6f60e6f8c471a38183f87757e3ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5258624
Reviewed-by: Aaron Krajeski <aaronhk@chromium.org>
Reviewed-by: Jean-Philippe Gravel <jpgravel@chromium.org>
Commit-Queue: Yi Xu <yiyix@google.com>
Cr-Commit-Position: refs/heads/main@{#1255711}